(a) Field of the Invention
The present invention involves a biodegradable triblock polyesteramide and preparation method, and furthermore pertains to synthesis of macromolecular materials. Products made from the biodegradable polyesteramide are primarily used in materials for environmental protection materials and biomedicine usage.
(b) Description of the Prior Art
J. Appl. Polym. Sci 20, 975(1976) discloses preparation of an amide-terminated polycaprolactone and fusion ester interchange reaction with polyethylene terephthalate (PET), acquiring an amide-chain distributed polyesteramide. However, materials from the preparation as disclosed have no application in biodegradable and environment degradation use.
Biological Chemistry, PP513˜521, E. H. Cordes, ed, Harper & Row, New York (1996); Polymer in Medicine II PP80˜85, E Chiellini ed, Plenum Press, New York (1966); E. J. Bioeng. 1,231 (1977); J. Biomed. Mater. Res.16,117 (1982); Trans, Soc. Biomater.6,109(1983), 7,210 (1984); Trans. Fourth World Biomaterials Congress 15,249,408 (1922); J. Biochim. Biophys. Acta 1042, 182 (1990); (U.S. Pat. No. 4,343,931) (1982); (U.S. Pat. No. 4,529,735) (1985). Aforesaid articles disclose reactions between hydroxy acetic acids and aliphatic diamines to synthesize aminediols, and revealing research into biodegradability and bioabsorbability of the products resulting therefrom.
Research has been carried out on derivatives of aminediols and aliphatic diacids to prepare biodegradable and bioabsorbable polyesteramides, and includes detailed composition tables of structure and properties, as well as disclosing preparation methods for use in medical surgical operation sutures, and applications in biodegradable artificial internal fastener devices employed in bone fractures. However, structural polyesteramides are quasi-crystalline macromolecular polymers, and speed of biodegradation is hard to regulate and control, and results in additional side effects appearing. Furthermore, reasons of cost results in the polymers not being extensively applied for environmental protection materials.
Journal of Chemistry 72. 867 (1972) discloses a L-lactic acid chain-linked polyesteramide. However, monomer synthesis is relatively complicated, and a polymer prepared therefrom behaves as a copolymer of L-lactic acid and poly-L-lactic acid amide. Further, P. R. China patent 9812899.7 discloses a polyesteramide copolymer containing a SL-lactic acid. However, synthesis of the polyesteramides is relatively complicated and is difficult to overcome occurrence of side reactions such as ester interchange, etc., as well as resulting in appearance of deep color changes in the polymers or copolymers prepared therefrom. Moreover, Kuhst Stoffe 85.(8),161 (1996) and (U.S. Pat. No. 5,644,020) discloses a category of diblock polyesteramides with melting point of 125° C., and mechanical properties equal to polyethylene. These diblock polyesteramides are able to quickly biodegrade under conditions that provides dampness and where humus exists.
Polymer, 39(2), 459(1998) discloses a preparation method having a carboxyl-terminated polyhexadiacidbutanediolester and hexadiacid as raw materials with cyclobutanol as a solvent. At a temperature of 200° C. a reaction occurs with 1.6 hexanediisocyanate, and produces a polyesteramide elastomer. However, the polyesteramide is unable to undergo biodegradation. P.R. China patents (99115200. X), (00112700. 4), (00112699. 7) disclose preparation methods for thermoplastic biodegradable polyesteramides and copolymers. Degradation is realized under acid conditions and a bioenvironment. However, toxic diisocyanate compounds are utilized during preparation of the polyesteramides, and thus have restricted application.